Compact Process Gas Monitor MICROPOLE System

Overview

The MICROPOLE system is one of the smallest complete mass spectrometer systems. The compact size is achieved by the patented design of miniature array of quadrupole mass filters. The array offers similar or greater sensitivity than conventional mass spectrometers but in a fraction of the volume. The system is capable of operating at much higher pressures than traditional systems, so the need for additional differential pumping equipment is reduced.

The sensors are factory pre-tuned and calibrated against transfer standards which allows direct interchangeability of the sensor by the user without the need for technical expertise to calibrate.

Features

High performanceMini array of 9 quadrupoles gives excellent sensitivity at a fraction of the volume of traditional quadrupoles.

High pressure operationCan be used at up to 0.9Pa (7mTorr, 9 x 10-3mbar) in many applications the need for expensive vacuum pumping is reduced or eliminated.

Interchangeable Sensor Head in calibrationThe sensor heads are pre-tuned and calibrated prior to shipment allowing the user to make sensor changes in the field without the need for fine tuning or technical expertise.

Network SensorsUp to eight sensors can be monitored by a single PC using RS-485. The systems can also be monitored remotely over Ethernet.

Specifications

Schematics

Measurement Techniques

■Measurement principle

The Residual Gas Analyzer consists of an ion source, a mass spectrometer, and a measurement section. The residual gas is ionized when it collides with the thermoelectrons discharged from the high-temperature filament, and the ions that are thereby created accelerate and converge onto the mass spectrometer. At the mass spectrometer, direct and alternating current voltages are applied to the four cylindrical electrodes (quadropoles), which allows the ions to be separated by mass. The separated ions are detected as electric current by the Faraday cup. The ion current is proportional to the mass (partial pressure) of the residual gas.

■MICROPOLETM Analyzer

The feature that makes the MicroPole? System unique is the MicroPole? Analyzer (MPA), a grouping of nine quadropoles that takes full advantage of ultraprecision optical etching processing technology and glass/metal joint technology. The development of the MPA has enabled the creation of the world's smallest residual gas analyzer, while offering the same or better sensitivity as conventional, larger mass spectrometers. The analyzer is a plug-in unit. It features a sensor unit that has already been calibrated for partial pressures, and offers absolute total and partial pressure measurement.

Applications

Downloads

Abstract"Concerning the dry process of the semiconductor device manufacturing, the monitoring of etching chamber conditions (pressure, temperature, gas concentration, ...) is crucial. This time, as a study of a new application, we examined the etching chamber management by using the residual gas analyzer.

Generally using a residual gas analyzer in a dry etching apparatus which uses halogen-containing gas has been being avoided because of concerns such as sensors life. By confirming the residual gas component in the chamber before etching, it was possible to illuminate the cleaning process."